The Cobra 8 has CryoDrive, where-as the Monster X does not. Learn more about CryoDrive here. Cobra 8 features an enhanced data logger over the Monster X; it allows for up to 20 samples per second (vs 10 on the Monster X). It also has 8x the storage capacity, records motor electrical timing and G-forces. It also has cyclical logging that never fills up and stops recording. The Cobra 8 also offers a reverse to forward brake and a reverse lockout timer. For crawling enthusiasts, it also boasts the new Hill Hold feature. Learn more about Hill Hold here.

By default the auxiliary wire is disabled and does nothing. If you are not utilizing this function you can leave the auxiliary wire (white wire) disconnected from the receiver. The auxiliary wire gives you the ability to adjust 1 of 8 ESC settings from your transmitter, via an auxiliary channel and dial/toggle switch, while you are operating the vehicle. To use this function you must program the auxiliary wire to one of the 8 available setting on the Castle Link; it is located on the “Advanced” tab. The 8 selectable settings are:

• None (Default) - AUX wire does not affect controller parameters.

• Max Throttle Adjustment - The controller's max power is controlled by the AUX wire signal. The power is scaled from 10% at 1.1ms signal received on the AUX wire to 100% at 1.9ms. If the AUX wire becomes disconnected, the controller will use the max forward and reverse powers set in Castle Link.

• Max Reverse Adjustment - The controller's max reverse power is controlled by the AUX wire signal. The reverse power is scaled from 10% at 1.1ms signal received on the AUX wire to 100% at 1.9ms. If the AUX wire becomes disconnected, the controller will use the max reverse power set in Castle Link.

• Max Brake Adjustment - The controller's max brake is controlled by the AUX wire signal. The brake strength is scaled from 10% at 1.1ms signal received on the AUX wire to 100% at 1.9ms. If the AUX wire becomes disconnected, the controller will use the brake strength set in Castle Link.

• Drag Brake Adjustment - The controller's drag brake is controlled by the AUX wire signal. The drag brake is scaled from 0% at 1.1ms signal received on the AUX wire to 100% at 1.9ms. If the AUX wire becomes disconnected, the controller will use the drag brake value set in Castle Link.

• Reverse Enable/Disable - Reversing is disabled when the AUX wire receives a signal above 50% (>1.5ms). When the controller receives an AUX wire signal below 50% or the cable becomes disconnected, reverse capability is enabled.

• Torque Control Adjustment - The controller's torque limit is controlled by the AUX wire signal. The torque control is scaled from 0.1 at 1.1ms signal received on the AUX wire to 5.0 at 1.9ms. Torque control is disabled when the input exceeds 1.9ms. If the AUX wire becomes disconnected, the controller will use the torque limit set in Castle Link.

• Idle Datalog Erase (Auxiliary Wire) - The controller will clear its data log when the AUX wire signal quickly alternates between greater and less than 50% (1.5ms) for a few seconds. This will only occur while the controller is idling.

• Rock Race/Crawler Mode - Allows you to change between Reverse Types and drag brake. Please refer to this page on our website for more details.

The fan on the Cobra 8 is thermally controlled. When you first power up the ESC it will do a power on self-test to show you the fan is functional. When the ESC arms the fan will stop running and then only turn on when the ESC reaches 140° F/60° C.

That’s what our expert technical support staff is for. Give them a call at 913-390-6939 or send them a message. They’ll be more than happy to assist you in deciding on a product.

Make sure the green LED is showing when you give forward throttle. If it is, then just swap any two of the ESC to motor wires to reverse the rotation direction of the motor (see note below for sensored operation). You may also reverse the direction of the motor using built-in manual programming, Castle Link USB adapter, or B-Link Bluetooth adapter. If the ESC shows the red LED with forward throttle, you will need to reverse your throttle channel on your transmitter (via a micro switch, or within the programming of the radio) and recalibrate.

Sensored motors: If you are running a sensored motor then you MUST keep A, B and C orientated properly. To change the motor direction with a sensored motor you must change the Motor Direction setting via the built-in manual programming or Castle Link USB adapter.

We have found that Spektrum has added a safety feature that interferes with our normal calibration and manual programming process. Our ESCs require you to power up the ESC at full throttle; the Spektrum SR6100AT receiver will not boot up properly until the throttle trigger is at neutral.
The solution we have found is to power up the ESC at neutral, wait for the receiver LED to turn solid amber, then apply full throttle; this allows the receiver to boot up properly.

WARNING: REMOVE Pinion gear or disengage motor from spur gear! You must apply full throttle BEFORE the ESC arms (double chime after LiPo cell count), but AFTER the receiver boots up and goes solid yellow. If the ESC arms and then you apply throttle the motor will run! We have found that waiting until the Auto LiPo feature counts the 3rd cell the receiver is operational and full throttle can be applied.

Yes! Although Cobra 8 and Castle brushless motors are waterproof, they are not intended for operation while completely submerged in liquid. They are designed to handle normal wet conditions like driving through puddles, wet grass and snow; they are not designed to be submerged like a submarine. The ESC can corrode when exposed to corrosive materials, such as salt water. Always rinse the ESC and motor with clean water after exposure to corrosives or dirt. While the motor and controller may be waterproof, we suggest users confirm that the rest of their vehicle, including the batteries, servos, radio and chassis are also waterproof before exposing them to liquids of any kind.
The fan must also be removed when exposed to wet conditions as it is not waterproof.

The sensor and receiver harness connection to the ESC can be affected by water; particularly salty, dirty or brackish water. Applying dielectric grease to the connections will help prevent signal interruption when wet and protect against corrosion.

Make sure the ESC is plugged into channel 2/throttle on the receiver, and that it's plugged in with the correct orientation. Double check your solder connections on the battery plug. Generally if you have no steering with everything plugged in correctly, then your receiver is either not getting power or not getting a signal from your transmitter.

The ESC should flash the yellow LED when it is armed; this indicates the ESC is logging data. If it is flashing yellow AND beeping, try moving the throttle trim one way, then the other (usually towards the throttle side is best). If your transmitter has a 50/50 and 70/30 setting for the throttle, set it for 50/50 and retry calibration.

Most calibration issues can be solved by settings on the transmitter. Make sure you have both your throttle and reverse endpoints (called EPA, ATV, or Travel on your radio) on the throttle channel out to 100 to 120%. If you have a Spektrum transmitter and have an “E” and “F” slider switch near your thumb, adjust the throttle dual rate slider out to the maximum value as well; some also have a "Throttle Limit" switch, amke sure it is set to 100. If you have a  "Brake Rate" setting, make sure it is turned full Clockwise. If you have a Futaba, Tactic or FlySky transmitter, set the throttle channel to the reversed position.

Replacement fans are available for sale through our retailers and our website. The part number is 011-0137-00.

No, all Castle speed controllers have a core value. You can visit our Repair Center for details on how to send in your ESC for non-warranty replacement. Or you can contact our repair department regarding details. 913-390-6939, or send them a message.

Cobra series ESCs must use the Castle Link V4 USB adapter and the Castle Link 2 program; they are not supported on the Castle Link V3 adapter and Castle Link Classic program. Make sure that on your Castle Link screen in the lower left hand corner you have a green USB connection status. If you do, the next step is to plug the ESC into the Castle Link. On the Castle Link circuit board just behind the three pins there are marks for positive (+), negative (-), and signal (Ω). The orange signal wire goes where the Ω pin is, the red goes where the “+” is, and the brown wire goes where the “-“ is. If you have disabled the red (+) wire going to the receiver you will need to plug in a battery pack to power the ESC. Anything above 2s LiPo will do. Plug the ESC in first, then the battery pack. The ESC should then connect. It will not work in the other order (battery first, then ESC to computer) so be sure to connect in the proper order.

You should use whatever your battery manufacturer’s recommendations are. Your speed controller came with a factory cutoff of 3.2v/cell. If you need to adjust this you can use a Castle Link or Field Link to program the speed controller for anything from 3.0v to 3.5v per cell.

The BEC can be set to from 5.0 to 8.0 volts in 0.1 volt increments via the Castle Link V4 USB programmer; the default is 5.5 volts.

That is a feature we added called the “Power On Warning Beep”. It lets you know that your battery pack is still plugged in whenever the speed controller is seeing zero throttle or no throttle from the transmitter at all. This is a safety feature implemented due to the advent of LiPo technology. You can disable it if you would like using the Castle Link USB programmer or B-Link Bluetooth adapter, but it is recommended that it be kept enabled.

No, it will not void the warranty as long as you only cut off the switch, solder the wires together, and cover them with shrink tubing on the outside the controller. Opening the controller and bridging the connection on the circuit board WILL void your warranty. ANY soldering on the speed controller will immediately void the warranty, no exceptions.